Summary
Workarounds
Use a Cloud Code beforeSave trigger to validate incoming data for prohibited keywords across all classes.
References
- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-q342-9w2p-57fp
- Fix Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.5.1-alpha.1
- Fix Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.12
Impact
The requestKeywordDenylist security control can be bypassed by placing any nested object or array before a prohibited keyword in the request payload. This is caused by a logic bug that stops scanning sibling keys after encountering the first nested value. Any custom requestKeywordDenylist entries configured by the developer are equally by-passable using the same technique.
All Parse Server deployments are affected. The requestKeywordDenylist is enabled by default.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
The fix replaces the recursive object scanner with an iterative stack-based traversal that processes all nested values without prematurely exiting the scan loop. This also eliminates a potential stack overflow on deeply nested payloads.
Frequently Asked Questions
- What is CVE-2026-30938? CVE-2026-30938 is a medium-severity security vulnerability in parse-server (npm), affecting versions < 8.6.12. It is fixed in 8.6.12, 9.5.1-alpha.1.
- Which versions of parse-server are affected by CVE-2026-30938? parse-server (npm) versions < 8.6.12 is affected.
- Is there a fix for CVE-2026-30938? Yes. CVE-2026-30938 is fixed in 8.6.12, 9.5.1-alpha.1. Upgrade to this version or later.
- Is CVE-2026-30938 exploitable, and should I be worried? Whether CVE-2026-30938 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-30938 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-30938?
- Upgrade
parse-serverto 8.6.12 or later - Upgrade
parse-serverto 9.5.1-alpha.1 or later
- Upgrade